Move fast dual method from MICOM

[cdiener]

• [X] description of feature/fix
• [X] tests added/passed
• [X] add an entry to the next release

This moves the fast dual methods from MICOM into optlang. This provides a quicker setup for primal/dual problems and multi-objective optimization.

Why?

• easier licensing
• method is not specific to MICOM
• code was originally adapted from convert_linear_problem_to_dual anyway

[Midnighter]

I'm a bit too far away from this at the moment, to be able to easily review. @KristianJensen can you take a look?